Langfuse vs PostHog
A side-by-side comparison of Langfuse and PostHog, drawn from Ignaite's continuously-verified listings.
Compared from listings verified as of
Langfuse
ObservabilityOpen-source LLM observability. Self-hostable, OpenTelemetry-native.
View LangfuseAt a glance
| Attribute | Langfuse | PostHog |
|---|---|---|
| Category (differs) | Observability | Analytics |
| Pricing | FREEMIUM | FREEMIUM |
| License | Open core | Open core |
| Deployment | Hybrid | Hybrid |
| Platforms (differs) | API, Web | Web, API |
| Model support | Model-agnostic | Model-agnostic |
| Vendor (differs) | Langfuse | PostHog |
| Capabilities (differs) |
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The honest brief
Langfuse
The MIT-licensed, self-hostable answer to LangSmith — own your observability data, framework-agnostic.
- Own your observability data
- Framework-agnostic, OTel-native
- Tracing + evals + prompt mgmt
- Transparent unit-based pricing
- Self-host infra cost at scale
- Less deep LangChain integration
- Setup heavier than hosted-only
PostHog
Folds LLM analytics into the same platform as product analytics, replay and flags — one stack instead of a separate AI-observability tool.
- Generous free tier (1M events/mo)
- Open source, self-hostable
- Auto-clusters LLM traces by behavior
- Usage-based pricing scales down
- Product breadth can overwhelm small teams
- Self-hosting supported at hobby scale only
- Lighter agent tracing than dedicated LLM-obs tools
When to pick which
Both cover LLM observability.
Pick Langfuse if you need LLM evaluation and Prompt management.
- LLM evaluation (secondary capability)
- Prompt management (secondary capability)
Pick PostHog if you need Data analysis / BI.
- Data analysis / BI (primary capability)
Langfuse leans on LLM observability as a headline capability; PostHog treats it as secondary.
- LLM observability (primary capability)